Remove enable drawing on unix switch (#64084)

* Remove enable drawing on unix switch

* Update some tests and not run tests that need Drawing on non Windows

* PR Feedback, just turn off the switch

Author: safern

src/libraries/Common/tests/TestUtilities/System/PlatformDetection.cs

@@ -87,34 +87,8 @@ private static bool GetLinqExpressionsBuiltWithIsInterpretingOnly()
             return !(bool)typeof(LambdaExpression).GetMethod("get_CanCompileToIL").Invoke(null, Array.Empty<object>());
         }
 
-        // Please make sure that you have the libgdiplus dependency installed.
-        // For details, see https://docs.microsoft.com/dotnet/core/install/dependencies?pivots=os-macos&tabs=netcore31#libgdiplus
-        public static bool IsDrawingSupported
-        {
-            get
-            {
-#if NETCOREAPP
-                if (!IsWindows)
-                {
-                    if (IsMobile)
-                    {
-                        return false;
-                    }
-                    else if (IsOSX)
-                    {
-                        return NativeLibrary.TryLoad("libgdiplus.dylib", out _);
-                    }
-                    else
-                    {
-                       return NativeLibrary.TryLoad("libgdiplus.so", out _) || NativeLibrary.TryLoad("libgdiplus.so.0", out _);
-                    }
-                }
-#endif
-
-                return IsNotWindowsNanoServer && IsNotWindowsServerCore;
-
-            }
-        }
+        // Drawing is not supported on non windows platforms in .NET 7.0+.
+        public static bool IsDrawingSupported => IsWindows && IsNotWindowsNanoServer && IsNotWindowsServerCore;
 
         public static bool IsAsyncFileIOSupported => !IsBrowser && !(IsWindows && IsMonoRuntime); // https://github.com/dotnet/runtime/issues/34582
 

src/libraries/System.Drawing.Common/src/System/Drawing/LocalAppContextSwitches.Unix.cs

@@ -7,14 +7,10 @@ namespace System
 {
     internal static partial class LocalAppContextSwitches
     {
-        private static int s_enableUnixSupport;
         public static bool EnableUnixSupport
         {
             [MethodImpl(MethodImplOptions.AggressiveInlining)]
-            get
-            {
-                return GetCachedSwitchValue(@"System.Drawing.EnableUnixSupport", ref s_enableUnixSupport);
-            }
+            get => false;
         }
     }
-}
+}

src/libraries/System.Drawing.Common/tests/System.Drawing.Common.Tests.csproj

@@ -2,7 +2,7 @@
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <IncludeRemoteExecutor>true</IncludeRemoteExecutor>
-    <TargetFrameworks>$(NetCoreAppCurrent)-windows;$(NetCoreAppCurrent)-Unix;net48</TargetFrameworks>
+    <TargetFrameworks>$(NetCoreAppCurrent)-windows;net48</TargetFrameworks>
     <IgnoreForCI Condition="'$(TargetsMobile)' == 'true'">true</IgnoreForCI>
   </PropertyGroup>
   <ItemGroup>